ELECTROMAGNETIC WAVE ABSORPTION SHEET
Provided is an electromagnetic-wave absorbing sheet of an electromagnetic-wave interference type that can favorably absorb electromagnetic waves in a frequency band equal to or higher than the millimeter-wave band and can be produced at low cost. The electromagnetic-wave absorbing sheet of an electromagnetic-wave interference type includes an electric resistance film 1 formed of a conductive organic polymer, a dielectric layer 2 having adhesiveness, and an electromagnetic-wave shielding layer 3 that are sequentially stacked. The sheet as a whole has flexibility. A thickness of the dielectric layer is set so that the dielectric layer can absorb electromagnetic waves in a frequency band equal to or higher than the millimeter-wave band.
1 . An electromagnetic-wave absorbing sheet of an electromagnetic-wave interference type, comprising an electric resistance film formed of a conductive organic polymer, a dielectric layer having adhesiveness, and an electromagnetic-wave shielding layer that are sequentially stacked,
wherein the sheet as a whole has flexibility, and
a thickness of the dielectric layer is set so that the dielectric layer can absorb electromagnetic waves in a frequency band equal to or higher than a millimeter-wave band.
2 . The electromagnetic-wave absorbing sheet according to claim 1 ,
wherein both of the electric resistance film and the dielectric layer have light transmittance,
the electromagnetic-wave shielding layer is constituted by a conductive mesh, and
the sheet as a whole has light transmittance having a total light transmittance of 30% or more.
3 . The electromagnetic-wave absorbing sheet according to claim 1 , wherein the dielectric layer comprises at least one adhesive selected from a silicone-based adhesive, an acrylic-based adhesive, and a urethane-based adhesive.
4 . The electromagnetic-wave absorbing sheet according to claim 2 , wherein the electromagnetic-wave shielding layer has a surface electric resistance of 0.3 Ω/sq or less.
5 . The electromagnetic-wave absorbing sheet according to claim 2 , wherein the electromagnetic-wave shielding layer has an aperture ratio of 35% to 85%.
6 . The electromagnetic-wave absorbing sheet according to claim 1 , wherein the electric resistance film comprises poly(3,4-ethylenedioxythiophene).
7 . The electromagnetic-wave absorbing sheet according to claim 1 , further comprising an adhesive layer on a surface of the electromagnetic-wave shielding layer on a side opposite to a side where the dielectric layer is disposed.